When using a flush valve in a toilet that has multiple lever or button options, it is possible to achieve an undesired flush, depending on user activation. An example is a dual flush toilet where there are two flush states: a partial flush and a full flush. The dual flush toilet valve can use a single cable mechanism assembly to control both flushes. The cable mechanism is controlled by displacing the cable different distances depending on partial vs. full flush. The cable then acts on a mechanism such as a lever assembly which raises a piston member, initiating a flush. The piston interfaces to different latch points for the different flush options. If the piston latches in the incorrect position, the wrong flush will be actuated. If the user activates the cable mechanism assembly quickly, it is possible for the inertia of the piston to cause it to travel past the intended latch point, into the region for the other flush latch position. Specifically, if a user is selecting a partial flush (in which the piston is only supposed to be raised to a first latch point), yet uses too much force too quickly, the piston can inadvertently travel fully upwards to the second latch position causing a full flush. What is instead desired is a system to avoid an inadvertent full flush when only a partial flush has been selected.